264 of 510 B2B SaaS companies publish an llms.txt, and only 52 publish the fuller llms-full.txt. SEO and content tools have the lowest adoption of any category. Adoption is widespread, but there is no public evidence the file improves AI visibility.
Key Takeaways
- 264 of 510 companies (51.8%) publish an llms.txt.
- Only 52 (10.2%) publish llms-full.txt, the version with real page content in it.
- The median llms.txt is about 12.8 KB, roughly a page or two of links.
- Adoption ranges from 70% to 23% by category. Design and no code tools lead. SEO and content tools come last.
- Google has said it does not use llms.txt, and no major AI company has committed to reading it for search answers.
llms.txt: A markdown file placed at yourdomain.com/llms.txt that gives AI systems a curated overview of a site and links to its most important pages. Jeremy Howard proposed it in September 2024.
Why Did I Run This Study?
llms.txt has become one of the most discussed ideas in AI search. The claims around it run well ahead of the evidence.
So I checked a narrow question: who is actually using it? I requested /llms.txt and /llms-full.txt from 536 B2B SaaS domains. 510 were reachable.
How Many B2B SaaS Companies Publish an llms.txt?
Just over half. 264 of 510 reachable companies publish an llms.txt. That is fast adoption for a file no major AI company has formally backed.
From domains checked to companies publishing the complete llms-full.txt file.
It says something about where established SaaS companies are focused. They want to be readable by AI and are willing to do the technical work.
One caveat: this sample is made up of well known SaaS companies. Adoption across the broader web is far lower, so read this as adoption among market leaders.
What Is the Difference Between llms.txt and llms-full.txt?
llms.txt is a short index of links. llms-full.txt includes the actual content of key pages in one file.
Only 52 companies publish the full version. Most shipped the minimum file and stopped. The ones that went further are mostly developer facing: Atlassian, Cloudflare, Databricks, GitHub, Grafana, CircleCI, Auth0, Deel, ClickUp and Buffer.
The median llms.txt is about 12.8 KB. A handful reach at least 400 KB, including Salesforce, Twilio, Datadog, Zendesk and Fivetran.
Which Categories Publish llms.txt Most?
Design and no code tools lead at 70%. SEO and content tools sit last at 23%. Communication tools reach 62% and DevOps and cloud infrastructure 60%.
Categories whose users already expect machine readable everything adopt fastest.
The SEO and content result has two readings, and both are worth holding. The obvious one: the companies whose business is search visibility are slow to adopt a new search visibility idea.
The less obvious one: SEO companies know better than most how little evidence exists that llms.txt does anything, and have chosen to skip it. My sample here is 13 companies, so treat the gap as a signal, not a verdict.
Does llms.txt Actually Improve AI Visibility?
There is no public evidence that it does. Google has been consistent on this, and no other major AI company has committed to reading the file for search answers.
| What it does | What it does not do | What is still unconfirmed |
|---|---|---|
| Gives AI tools a curated map of your most important pages | Help in Google Search, AI Overviews or AI Mode | Whether ChatGPT, Perplexity, Claude or Gemini read it when answering questions |
| Helps AI coding assistants find the right documentation | Block or restrict any crawler, which is still robots.txt’s job | Whether it shapes what future models learn about you |
| Makes you write down what your company is and which pages matter | Replace content quality, authority or third party mentions |
In June 2025, Google’s John Mueller wrote that no AI system currently uses llms.txt. A month later, Gary Illyes said Google does not support the file and has no plans to.
Google’s own 2026 guidance on optimizing for its AI features lists llms.txt among the tactics site owners can skip.
That matches what I see when I measure citations directly. In my analysis of 1,739 AI citations, recommendations came from independent content and well built comparison pages. A file at the root of your domain influences neither.
Should Your Company Publish an llms.txt?
- Yes, if you sell to developers. If your buyers use AI coding assistants to read your docs, llms.txt has a real use today.
- Otherwise, treat it as a byproduct. It takes an afternoon. The real value is writing down, in plain language, what your company is and which pages matter.
- Compare that description against your homepage, G2 profile and LinkedIn page. If they disagree, you have found a bigger problem than a missing file. I call it entity drift.
- Do not expect it to move AI visibility on its own. If engines are not recommending you, the causes are almost always thin comparison content and few third party mentions.
- Make sure robots.txt agrees with it. Thirteen companies in my crawler study publish an llms.txt while blocking an AI crawler.
What This Study Does Not Tell You
- It measures adoption, not effect. Half of market leaders publishing a file tells you it is popular and cheap. It does not tell you it works.
- It covers established companies. Smaller SaaS companies adopt far less.
- Some categories are small. Categories with fewer than 10 companies are excluded from the chart.
How I Ran This Study
I requested /llms.txt and /llms-full.txt from 536 curated B2B SaaS domains in September 2026. 510 were reachable.
A file counts as present only where it returns a valid text or markdown response. File size collection was capped at 400 KB.
How to Cite This Study
Dholakiya, P. (2026). llms.txt Adoption in B2B SaaS: An Analysis of 510 Company Websites. Growfusely. https://growfusely.com/blog/llms-txt-adoption-b2b-saas/
You are welcome to use the charts with a link back to this page.
Why Partner with Growfusely for AI Search Visibility?
I would rather tell you what a tactic does not do than sell it to you. llms.txt is a good example: cheap, popular and unproven for AI search.
- Evidence before tactics. My recommendations come from measuring what AI engines actually cite.
- An access and readability audit covering robots.txt, llms.txt, rendering and structured data.
- Entity consistency work, so the way you describe yourself matches across your site, review profiles and LinkedIn.
- Citation measurement across engines, so every change is judged on whether you appear in answers.
If you want an outside read on what AI engines currently say about your company, schedule a call.
FAQs
What is llms.txt?
A markdown file at yourdomain.com/llms.txt that gives AI systems a curated overview of a site and links to its most important pages. A companion file, llms-full.txt, includes fuller page content.
Does llms.txt Improve AI Search Visibility?
There is no public evidence that it does. Google has said it does not use the file, and no other major AI company has committed to reading it for search answers. Its clearest use today is helping AI coding assistants find documentation.
How Many Companies Publish llms.txt?
In my sample of 510 established B2B SaaS companies, 264 (51.8%) publish llms.txt and 52 (10.2%) publish llms-full.txt.
Is llms.txt the Same as Robots.txt?
No. robots.txt tells crawlers what they may access. llms.txt describes what a site contains. It cannot block anything.
Should my SaaS Company Publish an llms.txt?
If you sell to developers, yes. Otherwise it is optional and cheap. Do it for the discipline of describing your company clearly, and do not expect it to change how AI engines recommend you.
Read Next
- I checked 442 B2B SaaS sites for AI crawler blocking. Who blocks AI bots, and who blocks the wrong ones.
- Entity drift. Why AI engines hedge when your descriptions disagree.
- The discoverability stack. Where technical access fits in B2B discoverability.
Pratik Dholakiya is the Founder of Growfusely, a SaaS SEO and AI Search Visibility agency.
